The present invention relates to a golfer's practice swing device, and more particularly to a rigid rod type of mechanism, securable to the shaft of a golf club, for controlling the plane path, direction and radius of the golf swing arc of a user of the device.
Many devices have been previously developed intended for use by a student or regular golfer, to assist in improving his or her golf swing. Such devices generally have attempted to train the golfer to swing a particular club in a regular, proper fashion. To more readily appreciate the significant improvements and advantages which are believed to exist in applicant's invention over such prior art devices and to understand the manner in which the present invention differs, some of the theory behind a proper golf swing is believed to be useful.
Modern day theory of what is a "proper" golf swing imagines a large spoked wheel about a golfer as he or she addresses the ball, the hub or axis of the wheel being at the base of the golfer's neck and the lowest portion of the rim being at the ball. The golfer moves the club away, in the upswing, by turning his upper mass around the hub, keep the shaft more or less in the plane of that wheel with the head of the club following the rim of that wheel. At the top of the swing however, there is properly a slight shift in the path of the club head as it commences its downswing, brought about as golfer initiates the movement with his lower mass and keeps his upper mass movement passive. This causes the club head to return the downswing in an arc which is, for an average male golfer, at about an angle of 12.degree. inside the arc which the club head followed towards the end of the upswing, the shaft still however lying more or less in the plane of the imaginary spoked wheel. The head of the club, towards the lower part of the downswing as it approaches the ball, returns to a path approximately coincident with the arc-like path followed by the club head in the upswing. The change of path which the club head makes at the top of the backswing is called the "loop". Golf instructors feel that this "loop" of the swing is necessary to ensure not only that the face of the club hits the ball squarely, but also that the face of the club hits the ball on the target line towards the desired target towards which the ball is hit. (See for example article entitled "How To Slow Down Your Swing", "Golf Digest", June 1984, page 42 and article entitled "Feel The Wheel For Proper Plane" by Lou Skovran in "Golf Magazine", Nov. 1981, at page 54).
Another essential element of a proper golf swing is that of the crossover of hands (see article entitled "Crossover" by Harry Obitz in "Golf Magazine", Oct. 1982, at pages 32 and 33). For a right-handed golfer, in all good swings, the left hand must cross, or climb, over the right hand (pronation) as the player swings back. This motion occurs because the right arm folds on the back swing and the shaft of the golf club rotates to the right following the turn of the body. In the forward or downward swing, it reverses: the right hand crosses over the left as the shaft and body rotate to the left. "Crossover" is important because of the effect it has on the face of the head or blade of the club at impact with the ball. Assuming basic fundamentals, if the crossover is made prematurely in the forward swing, so that, at impact, the right hand is already crossed over the left, the blade of the club will be closed and a "hook" will result in the golf ball's trajectory. If the crossover is late, the blade will be open and a "slice" will result. Thus, to achieve proper pronation and supination, or as the result thereof, the club shaft must rotate to the right on the upswing and to the left on the downswing.
Golfer's swing practice devices which have been heretofore developed incorporate many different constructions. For example, one type requires no attachment to the golf club of the user. Instead it comprises tracts or guides, against which a part of the golf club is to bear during the swinging of the golf club by the user, to thereby control the orientation and position of the golf club when it is being swung. An example of such a device is found in Canadian Pat. No. 518,637 of Plunkett issued Nov. 15, 1955.
In another type, the device is in some way attached to a part of the golf club. Included in this type are those in which a flexible member such as a line or rope are anchored to an immovable object at one end and secured to a part of the golf club at the other (see for example U.S. Pat. Nos. 2,455,707 issued Dec. 7,1948 of Sheffer, 2,655,378 issued Oct. 13, 1953 of Sheffer; 2,788,214 issued Apr. 9, 1957 of Tilden and Canadian Pat. No. 872,391 issued June 1, 1971 of Gentry). Moller U.S. Pat. No. 3,738,661 issued June 12, 1973 describes and illustrates a golf exercising device comprising an anchored arm which is free to rotate about one axis and has a lower, flexible section. These practice devices having flexible lines or arms are not intended to train a golfer on proper crossover techniques during the golf swing; nor do they hold the club head in proper alignment on the target line with the respect to the ball. In this regard they permit the swing path to drift outside the target line (away from the golfer) a condition which in fact produces a slice.
Another kind of swing practice device which is secured to a portion of a golf club or practice handle is that which is made up of an articulated or rigid rod, anchored at one end and secured to the golf device at the other. Typical of such devices are those described and illustrated in Richards U.S. Pat. No. 4,261,573 issued Apr. 14, 1981, Jenks U.S. Pat. No. 2,626,151 issued Jan. 20, 1953, Cottingham U.S. Pat. No. 2,472,065 issued June 7, 1949 and Hetman et al Canadian Pat. No. 911,478 issued Oct. 3, 1972. Such devices have tended to be extremely complicated, requiring expensive, precisely manufactured and fitting mechanical hinges which among other things tend to bind. Because of their very complexity, many of these devices do not lend themselves to adaption to different sizes and frames of users and may require major mechanical alterations for users having different strength. They usually require expensive anchor stands or permanent anchor wall fixtures which cannot easily be repositioned or relocated. Such devices also tend to allow motion of the user's club face towards the ball, during a practice swing, such that the club face is not maintained on a swing path inside or on the target line. (One of the most prevalent problems a golfer faces is permitting the path of his club face on the downswing to go outside the target line, away from his body, resulting in a slice.)
Another background reference of interest is Garten U.S. Pat. No. 3,614,108 issued Oct. 19, 1971. This reference describes and illustrates a rigid rod secured at one end to a plate more or less permanently secured to a wall, the rod rotating as if on a fixed, truncated conical surface. A simulated golf club handle is affixed to the other end of the arm. Such device, while relatively simple, cannot provide for the required loop action at the top of the swing, with the result that the rod brings the user outside of the target line on the downswing. As well, such device does allow for pronation and supination of the hands of the user.
It is thus an object of the present invention to provide a simple, inexpensive golf practice swing device which will hold the swing of the user into a relatively accurate swing pattern and prevent the user from developing a swing path which drifts outside of the target line. It is a further object of the present invention to provide such a device which will at the same time urge proper pronation and supination of the golfer's arms during practice. It is a further object of the present invention to provide such a golf swing device which may be used in a variety of locations and which will work properly for a wide variety of frames, sizes and strengths of golfers.